Rechargeable batteries such as batteries made up of many lithium-ion cells can be used in many applications, including for example in electric vehicle (“EV”) and hybrid electric vehicle (“HEV”) applications. In a state of the art construction, individual battery cells are sandwiched between liquid-cooled heat exchanger panels, that is, inter-cell elements (ICE), having coolant circulation passages. The amount of heat removed from the cell is related to the flow rate of coolant through the plate. However, as the flow rate increases, the pressure drop also increases, thereby limiting the coolant flow rate and the cooling capacity of the panel.
Battery cooling fins (also known as inter-cellular element “ICE” plates) are generally made from very thin aluminum and have stamped channels through which coolant flows, for removing heat from the battery. As the structural integrity of the ICE plate is important, innovative techniques must be employed to ensure that the ICE plate channels do not collapse under the applied force of the batteries and of the manifold. Typically the channel dimensions are too thin to provide structural support from turbulizers inside the channels and therefore the channel dimensions are chosen such that they meet minimum load requirements.
In addition, at the entrance region of the channels a larger unsupported area exists so that coolant can be distributed to the various channels within the ICE plate. In some instances, such as the ICE plates with inlet/outlet tubes, radial seals can be used to secure a leak-free connection (see WO 2012/126111, incorporated herein by reference), however, in certain circumstances, for instance where matching up of the inlet and/or outlet of an ICE plate with a manifold is required without a tubular connection, and particularly in light of the extremely light gauge material of construction for the plates, a face seal can be more desirable. In addition, face seal can be generally easier to develop except special consideration needs to be applied to the structural integrity of the seal area.
In a face seal technique, a seal is pressed against a flat surface using a very high force. This flat surface must have enough structural integrity to prevent deflection of the sealing surface, otherwise a leak will form. Moreover, the plates should be able to withstand the clamping force and fitting load, when assembled. US 2006/0172177 A1 (incorporated herein by reference) discloses a method of face sealing by using under/over channels allowing for a flat sealing surface. However, it would be preferred to have the sealing surfaces align with each other through the plates to help reduce the likelihood of damage to the plates on sealing. Additionally, it is desirable to make the core plates symmetrical and to use the same seals for both the inlet and the outlet
There is a need for an improved construction of heat exchanger, and particularly battery cell coolers for rechargeable batteries while improving manufacturability, which can allow for the sealing surfaces to align with each other through the plates; and which can provide better force transfer and can help to reduce the likelihood of damage to the plate on sealing. In addition, there is a need for an improved construction of heat exchanger, and particularly battery cell coolers for rechargeable batteries that can help to provide a better sealing method so that the ICE plates are not being forced out of plane during clamping or pressure cycling. Furthermore, there is a need for an improved construction of heat exchanger, and particularly a battery cell cooler that can provide improved flow control towards more uniform flow distribution.